The infrared remote control is ubiquitous in daily life, controlling a wide variety of systems and devices. Infrared remote controls are provided with many modern devices, such as audio or video components. As a result, in even moderately complex systems, like home theater entertainment systems, the total number of remote controls used to separately control all the devices involved can quickly grow to an unmanageable size. For example, even in a relatively simple system, a user may have separate remote controls for a TV, a VCR, a DVD player, an amplifier, a CD player, and a cable control box. To address this complexity, a significant after-market has evolved in so called “universal” remote controls that perform the jobs of multiple specific remote controls. However, existing universal remote controls can only perform a limited subset of the functions that the device-specific remote controls they are intended to replace could accomplish. The user may thus be provided with a single remote control they can use most of the time, but still require multiple additional remote controls for occasional or regular use.
Compounding the limited utility of many existing universal remote controls is their inability to deal with a wide range of infrared frequencies. Most domestic U.S. infrared controlled devices operate using infrared frequencies in the 10 kHz to 125 kHz range, with some operating in the 455 kHz range. However, a small but significant percentage of U.S. devices operate outside of this range. Additionally, some European and Asian infrared controlled devices use other “out of range” frequencies. This situation causes problems with so called “learning” universal remote controls, since they cannot accurately learn infrared signals outside a typical expected frequency range.
To compound these problems, different infrared remote controls use different encoding schemes to transmit data to a controlled device. For example, some infrared remote controls use what is known as an RC5 code, which is a “Remote Control” code developed by Philips Electronics N.V., while others use an NRZ (Non-Return-to-Zero) type code, and still others use different proprietary codes. Thus a challenge also currently exists in correctly supporting different encoding formats.
Finally, the length of the required infrared signal can vary greatly between infrared controlled devices. Most infrared controlled devices require only a short burst of infrared signal, but there are some that require signals as long as two seconds.
The above and other issues make it difficult to build a single universal remote control that will work for all infrared controlled devices. However, there is a great need for a single infrared remote control that effectively operates with diverse controlled devices. This is especially true for situations where a user may be disabled in some way, and therefore unable to switch between multiple remote controls. For example, some users may need remote control capabilities provided under voice control, and/or under the control of one or more ability switches. Such ability switches may include sip and puff switches, tongue switches, blink switches, or other specific types of switches as required for a specific disabled person. In the case where an infrared remote control is voice or ability switch controlled, it should be able to fully operate all infrared remote controlled devices in the user's environment.
For the reasons stated above, in a complete solution, the following technical problems should be solved: i) the remote control should be able to handle any infrared signal frequency, ii) the remote control should be able to handle any type of encoding format, iii) the remote control should be able to handle any infrared signal length, and iv) the remote control should be able to conveniently handle large numbers of different infrared signals.